| 201 | O'Brien Operating Company | | Oil & Gas Operator | Dec 2004 |
| 202 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 203 | Oliditt Production Inc. | | Gas Operator | Sep 1998 |
| 204 | Ouachita Development Corp. | | Gas Operator | Mar 2014 |
| 205 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Mar 2025 |
| 206 | Pacific Atlantic Oil Co. | | Oil & Gas Operator | Dec 2003 |
| 207 | Palmer Petroleum Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Mar 2025 |
| 208 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |
| 209 | Panenergy La Intrastate Co | | Oil Operator | Mar 2000 |
| 210 | Pelican Producing Co. | | Gas Operator | Nov 1992 |
| 211 | Pelico Pipeline, LLC | | Oil Operator | Dec 2024 |
| 212 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 213 | Pete Caldwell Drilling Co.,Inc | | Oil & Gas Operator | Aug 1991 |
| 214 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 215 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 216 | Pine Pipeline, Inc. | | Oil Operator | Dec 1998 |
| 217 | Primos Oil & Gas Corp. | | Gas Operator | Dec 2001 |
| 218 | Primos Production | | Oil & Gas Operator | Dec 2024 |
| 219 | Primos-Pennzoil JV | | Gas Operator | Feb 2005 |
| 220 | Pruet Production Co. | Jackson, MS 39201 | Oil & Gas Operator | Dec 2024 |
| 221 | R. W. Ellington, Jr. | | Gas Operator | May 1985 |
| 222 | R. W. Wilson | | Gas Operator | May 1988 |
| 223 | Rabun Resources | | Gas Operator | Jan 2025 |
| 224 | Range Louisiana Operating, LLC | | Oil & Gas Operator | Aug 2020 |
| 225 | Red Rooster Gas Corporation | | Gas Operator | Sep 1993 |
| 226 | Regency Field Services LLC | Dallas, TX 75201 | Oil Operator | Jul 2017 |
| 227 | Regency Gas Gathrng & Proc LLC | | Oil Operator | Sep 2007 |
| 228 | Relco Exploration Co., Inc. | | Gas Operator | Aug 1987 |
| 229 | Reliant Energy Field SVS Inc. | | Oil Operator | Sep 2002 |
| 230 | Republic Gas Gathering Sys Inc | | Oil & Gas Operator | Nov 1981 |
| 231 | Richard T. Perry | | Gas Operator | May 1993 |
| 232 | River City Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Nov 1997 |
| 233 | River Energy Co., Inc. | | Gas Operator | Dec 2012 |
| 234 | Riverstone Energy Operating, LLC | Houston, TX 77090 | Oil & Gas Operator | Mar 2025 |
| 235 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 236 | Roberson Well Service | | Gas Operator | Dec 2024 |
| 237 | Robert G Cox & Assoc La Inc. | | Oil & Gas Operator | Jun 1994 |
| 238 | Rosamond Drilling Co., Inc. | | Gas Operator | Nov 1984 |
| 239 | Rowe, Inc. | | Oil & Gas Operator | Jun 1992 |
| 240 | Roy M. Teel | | Oil & Gas Operator | Nov 1983 |
| 241 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 242 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2024 |
| 243 | Saxon Oil & Gas Expl., Inc. | | Gas Operator | Nov 1989 |
| 244 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 245 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 246 | Segars Operating | | Gas Operator | Apr 2014 |
| 247 | Shiloh Creek Resources, Inc. | | Gas Operator | Nov 2024 |
| 248 | Shuler Drilling Co., Inc. | El Dorado, AR 71730 | Oil & Gas Operator | Sep 2024 |
| 249 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Dec 2024 |
| 250 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 251 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 252 | Spillers Petroleum, Inc. | | Gas Operator | Mar 2010 |
| 253 | Spirit Petroleum Company | | Oil & Gas Operator | Apr 1999 |
| 254 | Strahan Oil & Gas Co., Inc. | | Gas Operator | Oct 1983 |
| 255 | Strataform, Inc. | | Gas Operator | Jun 2002 |
| 256 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Mar 2025 |
| 257 | Summit Energy, Inc. | Littleton, CO 80127 | Oil & Gas Operator | Aug 2013 |
| 258 | Summit Overseas Expl., Inc. | Denver, CO 80226 | Oil & Gas Operator | Apr 2007 |
| 259 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 260 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 261 | T H Production Co. | | Oil & Gas Operator | Mar 1994 |
| 262 | Tahoe Corporation | | Gas Operator | Feb 2023 |
| 263 | Teel 78 A | | Gas Operator | Dec 1980 |
| 264 | Teel 79a | | Gas Operator | Dec 1980 |
| 265 | Tellus Operating Group, LLC | | Oil & Gas Operator | Dec 2024 |
| 266 | Tennessee Gas Pipeline Company | Houston, TX 77252 | Oil & Gas Operator | Dec 2011 |
| 267 | Tensas Delta Land Company | | Oil & Gas Operator | Apr 2002 |
| 268 | Terronne Petroleum Corporation | | Oil & Gas Operator | Nov 2024 |
| 269 | Texas Gas Transmission LLC | Owensboro, KY 42301 | Oil & Gas Operator | Dec 2024 |
| 270 | Thomas Aitken, Inc. | | Gas Operator | Dec 2024 |
| 271 | Tomlinson Oil Co. Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jun 2023 |
| 272 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 273 | Trans Ocean Oil, Inc. | Houston, TX 77252 | Oil & Gas Operator | Sep 1980 |
| 274 | Trico Oil Co., Inc. | | Gas Operator | Nov 1978 |
| 275 | Tulip Industries, Inc. | | Oil & Gas Operator | Feb 2024 |
| 276 | Twin City Gas | | Gas Operator | Nov 1997 |
| 277 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 278 | Tygr Operating Company, LLC | | Oil & Gas Operator | Nov 2024 |
| 279 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |
| 280 | Vernon E. Faulconer, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2024 |
| 281 | Viking Resources | | Oil & Gas Operator | Sep 1995 |
| 282 | Vista Investments | | Gas Operator | Nov 1998 |
| 283 | W. D. Roberson | | Gas Operator | Mar 2021 |
| 284 | W. J. Wegman, Jr. | | Gas Operator | Dec 1991 |
| 285 | W. M. Inabnet Agent | | Gas Operator | Oct 1985 |
| 286 | Weiser-Brown Operating Company | Magnolia, AR 71754 | Oil & Gas Operator | Mar 2025 |
| 287 | Wells-Battelstein O&G, Inc. | | Gas Operator | Dec 1986 |
| 288 | Whitton Company, Inc. | | Oil & Gas Operator | Jul 2020 |
| 289 | Wildhorse Resources, LLC | Houston, TX 77279 | Oil & Gas Operator | Feb 2015 |
| 290 | Will-Drill Production Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Mar 2025 |
| 291 | WM. Inabnet | | Gas Operator | Nov 2024 |
| 292 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 293 | Zadeck Energy Group Inc | | Oil & Gas Operator | Dec 2011 |